Thermostat knob construction



Nov. 11, 1941. K. B. DAFFORN IEI'AL 2,252,657

TNERMOSTAT KNOB CONSTRUCTION Fi ied March 24, 1941 Invjyntors A g 4;

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Aitovne s Patented Nov. 11; 1941 UNITED "STATES -PATENT [OFFICE THERMOSTAT KNOB CONSTRUCTION Kenneth ,B'. Dafl'orn and Russell I. Hufl'man,

Dover,

Ohio, assignors vto Knapp-Monarch Company, St. Louis, Mo., a corporation of Missouri Application March 24', 1941, Serial No. 384,922

11 Claims. (01. 74 424.22)

Our present invention relates to a thermostat knob construction wherein a knob of Bakelite or similar molded material may be inexpensively connected in an operative manner to a thermostat adjusting screw without the necessity of molding inserts into the knob. One object of the invention is to'provide a connecting element between a thermostat adjusting screw and a knob which-may be inexpensively fabricated in the form of a metal stamping and secured to the knob as by screws or the like, thus eliminating an expensive mold type of requiring In the accompanying drawing we have used the reference numeral III to indicate generally a sole plate and I2 a shell of a sad iron. Ahandle H is mounted on the shell [2 by means of front and rear supports l3 and I4.

The sad iron illustrated includes a bimetal element l which when heated to a predeter means for holding aninsert in proper position hold the knob closely adjacent the sad iron shell while the thermostatadjusting screw floats inwardly and outwardly as' a result of its screw threaded character and rotation being imparted to the screw by the knob.

. With these and other objects inview, our invention consists in the construction, arrangement and combination of the various parts of our device whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in our claims and illustrated in the accompanying drawing. Although the invention is susceptible of g. variety of embodiments,- it is unnecessary to fully dacribe and illustrate more than one in order to give a full understandmg of the invention both from its structural and functional standpoints.- Accordingly, I we have illustrated a preferred and desirable embodiment of the invention in the accompanying drawing,

in which 2 Figure 1 is an elevation partly in section of a" Figure 3 is a sectional view on the line 3-3 of Figure 1;

Figure 4 is a plan view of the knob per se, and

: Figure 5gis an inverted perspective view of a special type of washer used incur construction.

mined degree bends downwardly, as shown. to permit a contact spring It to be separated from a contact spring I! which it normally engages.

A stationary part 13 in the sad iron has a threaded bore l9 adapted to receive a thermostat adjusting screw '20. The screw 20 has an insulating button 20 on its lower end adapted to con- "tact with the spring I! and adjust it to thereby determine the temperature at which the contacts willbe separated.

A knob 26 is provided for rotating the adjustingscrew 20. A washer 22 is provided for con- 3 nesting the knob with the adjusting screw. For

this .purpose, the washer 22 at its center has a splined perforation 24 adapted to coact witha splined shank 2i of the adjusting-screw 20. This method of coaction permits sliding movement of the adjusting screw relative to the knob, but pre-' vents any rotation of one relative to the other whereby both must rotate together.

The knob 26 is provided with a bore 34 and with a counterbore 34". The washer 22 is adapted to fit in the counterbore 34' and to be secured therein by screws 25 extending through perforations 23 of the washer and into threaded sockets 25' of the knob. To additionally locate the washer in. the counterbore, the washer is provided with notches 21 and 23 adapted to receive projections 3|! and 31, respectively, of the knob in the counterbore. v

. The material that was initially in the notch 21 is bent downwardly to form a stop lug 23. :The lug 28 enters an opening 28 formed in the shell l2 and is adapted to cooperate with a stop lug 28 extending inwardly from the edge of the opening. The knob 23 is thus limited to slightly less than one revolution of adjustment.

Within the bore 3! a spring 32 is provided. The spring 32 is interposed between the washer 22 and the head of a screw 33 threaded into a bore 33* in the upper end of the adjusting screw 20. The spring 32 tends to keep the knob 26 against the shell i2, yet permits the slight longitudinal movement 'of the adjusting screw,relative to the knob occurring as a result of rotation of the screw threaded into the member 13.

My knob construction is such that the necessity of molding inserts into the knobjvhen itis formed is entirely eliminated ma ns element. 22 may" be-inexpensively formed as a stamping. Assembly involves merely the connection of the member 22 to the knob, after the spring 32 has been inserted in the bore 34, the placing of the knob in position on the adjusting screw and the j mounting of the screw 33 in position.

tending into-said bore of said knob, a spring in v Another feature may be mentioned with rei spect to the spring u; It'will be noted that the 1 spring is shouldered by reducing the diameterof the upper half thereof. Accordingly the lower half is retained between a constriction 34 of the i bore 34 and the washer 22 against displacement even though the screw 33 becomes lost. Nor- 1 mally of course the screw 33 is retained in position by being tight in" the threaded bore 33 of the adjusting screw 20 with compression of r the spring 32 tending to keep it tight.

Some changes may be made in the construc- 1 tion and arrangement "of the parts of our device without departing from the real spirit and'pnr- 1' pose of our invention, and it is our intention to.

cover by our claims any modified forms of structure or use of mechanical equivalents which may 'be reasonably included within' their scope with-- out sacrificing any of the. advantages thereof.

- We claim as our invention: I 1 1. In a knob construction, a knob of molded material or the like having a bore therethrough, f a washer, screws for retaining said washer I mounted against said knob, said washer havin a splined perforation at its center, an adjusting screw having a splined shank enteringsaid per.-

i'oration and 'extendinginto said bore of said knob, a spring in said bore having one 'end against said washer, and a screw in said shank having a head against the other end of. said spring. v e v 2. In a thermostatic knobconstruction, a knob of molded Bakelite or the like having a bore therethrou'gh, a counterborein the bottom of at its center to slidably and non-rotatably coact with said shank of said adjusting screw, said shank extending into said bore of'said knob, and

, spring means interposed between saidshank and periphery and said knob having a projection Y said knob, a washerin said counterbore, means for retaining said washer mounted in said counterbore, said washer having a splined perforation at its center, a thermostat adjusting'screw having a splined shank entering said perforation and extending into said bore of said knob; a spring in said bore having one end *against said; washer, anda screw in said shank having a head against the other end of said spring to urge said j knob longitudinallyoi saidshaft and to pemiit longitudinal movement of said adjusting screw through said perforation withv the'knob remaining operatively connectedwith the screw to rotate it.

v 3. a knob construction comprising a knob and means for connecting said knob with an adjust- 1 ing screw or the likecomprisii ig a disc, screws T for retaining said disc mounted on said knob,

? .said disc having a splined perforation, an adjusting screw having a splined shank entering said perforation and extending into said boreof said washer to retain said knob in-position closely adjacent said shell and permit longitudinal movement of said adjusting screw relative to said knob as the knob is rotated for adjusting the screw. 1

6. A thermostatic knob construction compris ing a knoboimolded material or the like having a bore and-a c'ounterboraa washer in said counterbore, said washer having a notch in its extending into said counterbore and entering said notch,1means for securing said washer in said counterbore, said washer having slidable and non-rotatable connection with the shank of said adjusting screw, said shank extending into said knob, andspring means interposed between'said shank and said washer to urge said knobinadire'ction toward said shell. I

7; A thermostatic knob construction comprising a knob of molded material or the like having a bore and a counterbore, a washerin said counterbore, said washer having -a notch in its periphery and said knob having a projection extending into said ,counterbore and entering said notch,'means for securing said washer in said counterbore, said washer having a splined Z perforation, a thermostatadjustin! screw having a splined shank extending through a persaid knob, a spring in said bore having=on'e end against said washer, and a screw in saidshank having a head against the other end of said 1 spring to urge said knob longitudinally of said screw.

4. In a thermostatic knob construction, a-knob of molded materiakhaving a bore therethrough, a counterbore in the bottom of said knob, a

ing said washer mounted in said counterbore,' said washer having a splined perforation at its center, a thermostat adjusting screw having a foration in a sad iron shell or,the like, said washer having a stop lug depending therefrom,

said perforation of, said shell having a cooperating stop lug extending inwardly from the edge of the shell perforation to limit rotation of said adjusting screw, said splined perforation of said washer slidably-and non-rotatably coacting with said shank of said adjusting screw,

.said shank extendingint; said bore of said knob. 4 and spring means interposed between said shank and said'washer'to retain said knob in position. closely adjacent said shcliand permit longitudinal movement of said a djusting screw relative to-said knob'as the knob is rotated for adjusting the screw. L

8. A thermostatic knob construction compris ing a knob having a bore and a counterb'ore, a

washer in said counterbore having Oppositenotches, means for securing said washer in said counterbore, projections from said knob into said washer in said counterbore, screws for retainsplined shank entering said perforation and. ex-

counterboraand entering said notches, said washer having an other-than-round perforation,

a thermostat adjusting screw having an otherthan-round, shank slidable and non-rotatable in said perforation of said washer, and means to urge said knob in one direction longitudinally of said adjusting screw) 9. A thermostatic knob construction comprising a knob having a bore and a counterbore, a washer in I said counterbore having opposite notches, means for securing said washer in said counterbore, projections from said knob into said counterbore and entering said notches, said washer having a stop lug bent away from the knob at the bottom of one or said notches and having an other-than-round perforation adjacentits center, a thermostat adjusting screw having an other-than-round shank slidable and non-rotatable in said perforation of said washer,

,a shell for the thermostat and having an opening through which said adjusting screw extends, said opening receiving said stop vlug and said shell having a cooperating stop lug extending inwardly from the periphery of said opening, and

means to prevent dislocation of said knob from said adjusting screw.

10; A thermostatic knob construction comprising a knob having a bore, a washer secured to the bottom of said knob, said washer having an other-than-round perforation adjacent its censaid bore having a constriction to 'coact with the ter, a thermostat adjusting, screw having an 20 other-than-round shank slidable and non-rotatable in said perforation, a shell for-the thermostat and having an opening through which said adjusting screw extends, said bore of said knoo having a constriction, a spring in said bore between said adjusting screw and said washer, said spring having an enlarged part retained between said constriction and said washer.

11. A knob construction comprising a knob having a bore, a washer secured to said knob, said washer having a splined perforation at its center, an adjusting screw having a splined shank extending to slidably and non-rotatably coact with said washer, said shank extending into said bore of said knob, a spring interposed between said shank and said washer to retainsaid knob in position, said spring being shouldered, and

shoulder thereof.

' RUSSELL I. HUFFMAN.

KENNETH B. DAFFORN. 

